So far we have done a lot to build a low-carbon economy, but it is ____ ideal (理想). We have to work still harder. 

----You look tired, Jack. ----I feel quite rested, _______.

He had promised me to come to the party, and _____.

--How ___ do you go to the cinema?---Once a week.

—Why are you so late?—The driver couldn’t see clearly because of the fog．____, the road was too icy．